The present invention relates to turbine engine arrangements and more particularly to electrical machines associated with turbine engine arrangements in order to provide electrical power generation.
Operation of turbine engines is relatively well known and clearly involves airflows which pass through compressor and turbine stages in order to generally provide propulsion in an aircraft or usable power in a stationary engine. An electrical starter motor may be provided in order to create initial rotation of the compressor and turbine stages such that there is engine pick-up upon combustion. Subsequently, the starter motor is then decoupled in order to avoid drag upon the engine. Alternatively, and particularly with aerospace applications, a pneumatic starter may be used.
More recently the starter motor has more generally been configured as an electrical machine whereby at engine start-up it can as indicated previously provide short term engine rotation before combustion pick-up and subsequently take power, normally through the same coupling, in order to generate electrical current for engine operations and other functions such as air conditioning equipment. It will be understood with increasing amounts of control equipment and possibly ancillary apparatus such as air conditioning equipment there is an increasing demand for electrical power. Thus, there is a desire to more conveniently generate such electrical power whilst limiting any diminishment in underlying turbine engine operation.